t3a.small

Analysis

The t3a.small is a general purpose instance in the t3a series with 2 vCPUs and 2 GiB of memory on AMD EPYC 7571 (up to 2.5 GHz), which makes it very compute-heavy at 1 GiB of memory per vCPU.

Running it in Mumbai instead of São Paulo saves $13.07 a month per instance: $0.0123/hour against $0.0302/hour, a 146% spread.

At $0.0188/hour on demand in US East (N. Virginia), about $13.72 a month, the t3a.small is one of the cheaper ways to buy general purpose capacity: only 3% of the 354 current general purpose types cost less per vCPU-hour than its $0.00940.

It is the cheapest of the 2 processor variants AWS sells at this size and generation. The t3.small on Intel Skylake E5 2686 v5 costs 11% more, and no others also sit above it.

It is size 3 of 7 in the t3a series. Stepping up to the t3a.medium gives 2 vCPUs and 4 GiB for $13.72 more a month. Dropping to the t3a.micro saves $6.86 a month. Unit price is not flat across the series ($0.00235 to $0.0376 per vCPU-hour), so the size changes the rate you pay.

Reserving it for a year with no upfront payment cuts the Linux rate to $0.0118/hour, which beats on demand once it runs more than 63% of the time; three years brings it to $0.00810/hour, 57% below on demand. Windows Server roughly doubles the bill at $0.0372/hour, because the licence is charged per vCPU.